Rainfed and Supplemental Irrigation Modelling 2D GIS Moisture Rootzone Mapping on Yield and Seed Oil of Cotton (Gossypium hirsutum) Using Precision Agriculture and Remote Sensing

The effects of two irrigation (IR1: rainfed; IR2: rainfed + supplemental drip irrigation), and two fertilization (Ft1, Ft2) treatments were studied on cotton yield and seed oil by applying a number of new agro-technologies such as: TDR sensors; soil moisture (SM); precision agriculture; remote-sensing NDVI (Sentinel-2 satellite sensor); soil-hydraulic analyses; geostatistical models; SM-rootzone, and modelling 2D GIS mapping. A daily soil-water-crop-atmosphere (SWCA) balance model was developed. The two-way ANOVA statistical analysis results revealed that irrigation (IR2 = best) and fertilization treatments (Ft1 = best) significantly affected yield and oil content. Supplemental irrigation, if applied during critical growth stages, could result in substantial improvement on yield (+234.12%) and oil content (+126.44%).

EVALUATION OF RAINFED AGRICULTURE MANAGEMENT PRACTICES AS AN APPROACH FOR SUSTAINABILITY IN NORTHWESTERN COAST (NWC), EGYPT

Sustainable development can be possible in rainfed agriculture by integrated approach of soil management measures. Soil quality in the form of a quantitative index is used as an indicator of environmental quality and sustainability. Twelve farms selected to achieve the targets of the present investigation (six farms under traditional rainfed agriculture system and six farms under rainfed with supplemental irrigation) at Northwestern Coastal Zone (NWCZ). These farms varied in land use and management practices concerning fertilization practices, tillage system, crop type and cultivated period. This study selected some soil indicators vis-à -vis soil physicochemical properties of the selected farms of studied areas at NWCZ. The rating of soil quality index (SQI) and relative of soil quality (RSQI) values in this study were higher towards to rainfed agriculture with supplement irrigation farms than in traditional rainfed farms. In addition, most of the values of soil quality change (∆RSQI) were moderately increase (class II) and most of these farms were under traditional rainfed management. The results of cumulative rating index CRI showed a negative correlation and significant relationship with RSQI (R2=0.82, p<0.05). concerning the impacts of soil quality on productivity, the relationship between relative yield (Ry %) and RSQI was positive significant correlation (R2=0.78, p<0.05). Also, CRI showed negative significant correlation with Ry% (R2=0.81, p<0.05). Moreover, the highly soil quality class I, highly sustainability, low changes in soil quality and highly crop yield observed was in the farms under rainfed with supplemental irrigation system and good fertilization practices (NPK+organic manure). So, this study recommended to expansion rainfed with supplemental irrigation management system and add suitable dose of NPK application with manure along scientific lines to encourage crop yields that can be achieved on a sustainable basis, but it need a long time to reach class I quality and highly sustainable status.

Comparison of physiological response to growth stage-based supplemental and conventional irrigation management of wheat

A field experiment was carried out to evaluate the effect of different conventional and supplemental irrigation strategies on leaf stomatal conductance (gs) and chlorophyll content (SPAD) yield and irrigation water productivity (IWP) of wheat using sprinkler line source in 2014 and 2015 in the Mediterranean region. The irrigation strategies were, supplemental irrigation (SI) during flowering and grain filling (SIFG), SI during grain filling (SIG), SI during flowering (SIF) and conventional irrigation (CI). These strategies were conducted under four irrigation levels 25, 50, 75, 100% and a rain-fed as control. The results indicated that CI100 and CI75 produced the greater grain yield and IWP, respectively. CI100 resulted in the increased chlorophyll content by 8.8% over rain-fed. The results confirmed that the SPAD and stomatal conductance values were not equally sensitive to water stress during growth stages. The wheat crop suffered a greater SPAD and gs reductions when the water stress occurred during the grain filling stage (SIF strategy) compared to other strategies, which means that the grain filling stage is more sensitive and effective to decrease the yield of winter wheat. The higher grain yields were achieved when the seasonal mean gs reached 207.4 mmol/m2s in CI and 169.2 mmol/m2s in SI, and the stomatal closure responded well to low, moderate and severe drought treatments. The leaf stomatal conductance (gs) was correlated linearly with grain yield. These relations could be used as a physiological indicator to evaluate water stress effect on the growth and productivity of wheat.

Effects of supplemental irrigation on yield, water use efficiency and nitrogen use efficiency of potato grown in mollic Andosols

Background Low soil fertility and reduced seasonal rainfall contribute to low potato (Solanum tuberosum L.) yield in Kenya. Nitrogen (N) deficiency is the major problem facing by the smallholder farmers of Kenya due to lack of fallow. Hence an introduction of supplemental irrigation with an adequate application of this nutrient could increase potato yield. The objective of this study was to determine the effects of supplemental irrigation and N-fertilisation on potato tuber yield, water use efficiency (WUE) and nitrogen use efficiency (NUE). The experiment was conducted in Nakuru County, Kenya for two seasons. The experimental soils are classified as mollic Andosols. The treatments comprised two irrigation treatments of full supplemental irrigation (FI) and rainfed production (RF) and four N levels of four N levels of 0 (N0), 60 (N1), 90 (N2) and 130 kg N/ha (N3). Results The results showed that total tuber yield, marketable tuber yield and NUE were significantly (P < 0.001) affected by irrigation × N-fertilisation while WUE was only affected (P < 0.001) by N-fertilisation. The highest total tuber yield, 58.28 tonnes/hectare (t/ha), was recorded under FI combined with N3. Treatment FI significantly increased marketable tuber yield by approximately 125.58% in all N treatments compared to RF. The highest NUE of potato (236.44 kg/kg of N) was obtained under FI combined with N3 but not significantly different from the NUE of potato obtained under FI with N2. N-fertilisation N3 produced the highest WUE of 14.24 kg/m3. Significant correlation was obtained between tuber yield and number of tubers/plant (r = 0.75, P < 0.001), NUE (r = 0.95, P < 0.001) and WUE (r = 0.72, P < 0.001). Conclusion High potato yield and marketable tuber yield can be achieved in mollic Andosols when water deficits of the growing season are eliminated with supplemental irrigation and an application of 130 kg N/ha.